The research proposed will continue to have as its principal objectives delineation of the role of the autonomic nervous system in regulating secretory activity and growth of salivary glands of adult and immature rats. For these studies we will continue to use the in vivo whole parotid and submaxillary glands as well as the in vivo perfused submaxillary duct of the adult rat to assess the role of both branches of the autonomic nervous system and its receptors. Direct nerve stimulation, with and without antagonists, or specific receptor agonists will be used. Substance P has generally been assumed to have no action on the autonomic receptors of the effector gland and is also being examined since new evidence points to a dual receptor action in evoking salivary secretion. The role of Substance P in regulation of ion secretion will be examined using whole parotid and submaxillary. In addition, effects of Substance P in transport of Ca, Na, K and Cl in the in vivo perfused submaxillary duct will also be examined. The reserpinized salivary gland will be the object of additional studies to determine whether, from physiologic evidence, the reserpinized gland is an appropriate model for study of cystic fibrosis since a variety of agents can cause effects similar to those induced by reserpine. The elucidation of autonomic regulation of postnatal growth and differentiation of salivary glands will be continued, and surgical, dietary and chemical means will be used for this work.